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Why is Firefox so slow after the upgrade to OS X Lion? Safari opens pages immediately, like Firefox on Windows, but on Lion it can easily take up to 30 seconds.

Posted

Running OS X Lion 10.7.1 Mac mini early 2009, 4GB RAM. No other problems except both Firefox and Chrome are incredibly slow opening web pages when compared to the same two browsers in Windows or to Safari in OS X.

This happens whether other applications are running or not. Internet speed has not changed (tested 6 Mbps), not using proxies, etc. Yes, I did test after Quitting all other apps. It makes no difference.

Chosen solution

I have the same problem, FF and Chrome are really slow to begin downloading the page, FF and Chrome are at full speed when I go into bootcamp.

It might have something to do with IPV6, this worked for me: http://markandkelley.com/mark/2011/09/fixed-firefox-6-and-slow-browsing-on-lion/

Read this answer in context 9

Additional System Details

This happened

Every time Firefox opened

This started when...

After upgrade to OS X Lion and Fiorefox upgrade.

Installed Plug-ins

  • iPhoto6
  • Office Live Update v1.0
  • Microsoft Office for Mac SharePoint Browser Plug-in
  • Displays Java applet content, or a placeholder if Java is not installed.
  • The QuickTime Plugin allows you to view a wide variety of multimedia content in web pages. For more information, visit the QuickTime Web site.
  • Shockwave Flash 10.3 r183

Application

  • User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:6.0.2) Gecko/20100101 Firefox/6.0.2

More Information

Troubleshooting Information
This page contains technical information that might be useful when you're
trying to solve a problem. If you are looking for answers to common questions
about Firefox, check out our support web site.
Application Basics
Name
Firefox
Version
6.0.2
User Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:6.0.2) Gecko/20100101 Firefox/6.0.2
Profile Directory
Enabled Plugins
about:plugins
Build Configuration
about:buildconfig
Extensions
Name
Version
Enabled
ID
Modified Preferences
Name
Value
browser.places.smartBookmarksVersion2browser.startup.homepage_override.buildID20110902133214browser.startup.homepage_override.mstonerv:6.0.2browser.tabs.loadInBackgroundfalseextensions.lastAppVersion6.0.2network.cookie.prefsMigratedtrueplaces.database.lastMaintenance1314993871places.history.expiration.transient_current_max_pages120795privacy.clearOnShutdown.offlineAppstrueprivacy.sanitize.migrateFx3Prefstrueprivacy.sanitize.sanitizeOnShutdowntruesecurity.warn_viewing_mixedfalse
Graphics
Adapter Description0x22600,0x20400WebGL RendererNVIDIA Corporation -- NVIDIA GeForce 9400 OpenGL Engine -- 2.1 NVIDIA-7.4.10GPU Accelerated Windows1/1 OpenGL

screwu2 0 solutions 1 answers

Firefox is incredibly slow in Lion. Even a simple click on a tab can take a second or so to switch. And it beachballs all the time, too. I love FF, but this is too much!

kolion-padthai 1 solutions 6 answers

See https://support.mozilla.com/en-US/que.../676180#answer-22243

Modified by kolion-padthai

Question owner

I run very few or no extensions with the exception of Java and Flash. I never, NEVER use stupid toolbars. The problem with FireFox on OS X Lion seems to be related to the OS. The speed of my Internet connection never changed and it continues to be fast for all of my computers, both Mac and Windoze 7.

If you change your default DNS on the Mac to something like the IP address of the Google DNS servers, FireFox and Chrome will run at normal speeds. If anyone needs help with this, please post another message and I will post instructions.

jasher 0 solutions 1 answers

Please post instructions! I have two MacBooks (one running Snow Leopard and one running Lion) and the Snow Leopard one is fine, while the Lion one struggles to even open my home page.

dmmd123 1 solutions 1 answers

Chosen Solution

I have the same problem, FF and Chrome are really slow to begin downloading the page, FF and Chrome are at full speed when I go into bootcamp.

It might have something to do with IPV6, this worked for me: http://markandkelley.com/mark/2011/09/fixed-firefox-6-and-slow-browsing-on-lion/

pnb470 0 solutions 2 answers

Helpful Reply

dmmd: Thank you so much! Incredible, like night and day! I upgraded to Lion just 2 days ago. Since my iMac is late 2007, I got a Snow Leopard disc to start with. Running 4GB of Ram, so should be no problem. Snow Leopard was fine, but Lion was like quicksand. Your post was one of the best fixes I've ever run into. Again, thanks!

Modified by pnb470

Lowestoftboy 0 solutions 1 answers

I've been using Firefox for ages without problems until upgrading to OSX 10.7 Lion. Since the upgrade however, start-up times were taking forever, the internal drive was ticking away furiously and a look at the disk usage in the Activity Monitor application confirmed a crazily high volume of data being written to and from the drive. Close to giving up on Firefox I followed the advice posted here by dmmd123. It took less than a minute to carry out the instructions, nothing scary or difficult, Firefox start-up is now totally transformed and takes just a few seconds. The simplest fix for the most dramatic improvement I've encountered in 22 years of using Macs. So impressed was I that found myself quitting and rebooting Firefox a few times just for fun! Thanks so much for the fix, I don't understand what it did but it just worked. Highly recommended for anyone experiencing this problem.

M-Gareth 0 solutions 1 answers

Comment hidden from user pretending to be moderator

Modified by Noah_SUMO

2SHADES 0 solutions 2 answers

[Insults removed by moderator. Please read Forum rules and guidelines and remember that this forum is for helping people, thanks.]

Modified by Chris Ilias

Question owner

First of all, who do you think you are to talk to anyone like you did in your reply? Let me make this short. You are very late and unjustifiably, unnecessarily insulting. If you are having a bad day, take a pill and get off this site. None of us need people like you.

This problem is well known to an awful lot of good people, and far more experienced than you. Just to set the record straight, few people, if anyone, are blaming Firefox. We were trying to identify the problem and find a solution because we like the product so much. You don't deserve to know what the problem was (did you read that correctly? ...was), and I hope the folks at Mozilla shut down your account for good!

2SHADES 0 solutions 2 answers

[Insults removed by moderator. Please read Forum rules and guidelines and remember that this forum is for helping people, thanks.]

Modified by Chris Ilias